Traffic Control and Work Zone Safety for High Volume Roads NJDOT Research Showcase 10/27/2011
Background o NJDOT surveyors and inspectors conduct their work mainly in a quickly changing work environment and are exposed to traffic. o The safety precautions they utilize are orange vests, hazard signs and strobe lights on top of their vans. o MUTDC guidelines do not specifically and adequately address the needs of this type of temporary work zones.
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Scanning Steps of Research Literature Review of work zone control and safety issues and technologies with an emphasis on high speed roadways. Interviews with other States. Data Collection Site visits Field Data. Develop Recommendations Selection and Assessment of Most Promising Technologies
State of Practice The research team conducted phone interviews with Rhode Island, New York, Connecticut, Texas, Maryland, Oregon, Florida, Washington and Wisconsin. It was learnt that surveyors and inspectors use the same MUTCD guidelines as others who work at work zones whether the work is temporary or not. There are no guidelines specific to surveyors and inspectors who work on high speed high volume roadways. 5
Site Visits Site visits were conducted with bridge inspectors, land surveyors and geodetic surveyors. The visits were not only for collecting safety data, but also to understand the nature of their work. The visits were quite informative as to how these crews work and ensure their safety during field tests.
Bridge Inspectors: Site Visits Minimum exposure to traffic. Inspectors mostly work behind bridge guardrails. They park on the shoulder or on the median, or park in a lot close to the bridge and walk to the site. When working on freeways and interstate highways they are accompanied by attenuator trucks. They use cones only if parked on the pavement. Duration of their work varies between 30 minutes to 1.5 hours Location Date I-78, Lebanon, NJ June 14, 2011 Route 33, Howell, NJ June 15, 2011 Route 31, Lebanon, NJ June 28, 2011 I-78, Bloomsbury, NJ June 28, 2011 Route 41, Lakeland, NJ June 30, 2011 Route 55, Vineland, NJ July 13, 2011 Route 130, Camden, NJ July 15, 2011 Route 33, Neptune, NJ Sept 16, 2011 7
Geodetic Surveyors: Exposed to traffic Duration of their work is less than 5 minutes Site Visits They work behind the van with strobe light on top parked on the shoulder They take GPS measurements of the predetermined locations on the map, and move to another location Therefore, a detailed set up including several video cameras and radar speed guns would not be fitting for this type of surveying Location Date Route 30 - Absecon, NJ 11/12/2010 Route 30 - Absecon, NJ 11/18/2010 Route 70 - Cherry Hill, NJ 11/19/2010 Route 55, Millville, NJ 05/03/2011 Route 55, Millville, NJ 05/05/2011 8
Land Surveyors: Site Visits Exposed to traffic They mostly work on local streets / state routes traffic intersections and railroad crossings. They use Survey Crew Ahead Signs and reflective vests only. Duration of their work varies between 45 minutes to 3 hours Location Date Route 64, Princeton, NJ 06/04/2010 Route 35, Belmar, NJ 06/09/2011 Route 33, Neptune, NJ 09/16/2011 Ryders Lane, New Brunswick, NJ 09/27/2011 Ryders Lane, New Brunswick, NJ 09/29/2011 Ryders Lane, New Brunswick, NJ 09/29/2011 Veronica Avenue, Somerset, NJ 10/05/2011 Veronica Avenue, Somerset, NJ 10/07/2011 Route 27, New Brunswick, NJ 10/11/2011 Route 27, New Brunswick, NJ 10/17/2011 Jersey Ave, New Brunswick, NJ 10/21/2011 9
Data Collection The premise of the field data collection is to identify possible safety problems involving surveyors and inspectors. The extracted data from video recordings are volume by lane, speed and lane changes These measures present how exposed surveyors and bridge inspectors to traffic. Each video was analyzed frame-by-frame to measure accurate speed of each vehicle traveling on the lane closest to the surveyor. 10
Frequency (%) Route 31 Bridge Inspection Data 25.0 20.0 15.0 10.0 5.0 0.0 50 52.5 55 57.5 60 62.5 65 67.5 70 Speed (mph) Average Speed = 54.9mph Standard Deviation = 5.9 mph Maneuver Count Percentage No change 296 96.7 Slight change or attempt to change 7 2.3 Lane change from left to middle 3 0.98 Lane change from middle to right 0 0.0 306 11
Frequency (%) I-78 Bridge Inspection Data 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 50 55 60 65 70 75 80 Speed (mph) Average Speed = 64.4 mph Standard Deviation = 6.27 mph Maneuver Count Percentage No change 1157 96.4 Slight change or attempt to change 41 3.4 Lane change from left to middle 0 0 Lane change from middle to right 2 0.2 1200 12
Geodetic Surveying Data Location Duration (minutes) Lane 1** (veh) Lane 2 (veh) Lane 3 (veh) Lane Change (%) Total Volume (veh) Route 70* 3:16 35 49 49 7.5 133 Route 70* 4:24 19 53 49 6.6 121 Route 70 3:27 85 74-5.7 159 Route 70 3:08 54 42-1.0 96 Route 30 1:03 22 13-5.7 35 *Indicates downstream of a signalized intersection. ** Indicates the lane closest to the surveyor. 13
Frequency (%) Route 70 Geodetic Surveying Speed Distribution Route 70 Minimum: 8.2 mph, Maximum: 61.3 mph, Average: 34.9 mph 25.00 20.00 15.00 10.00 5.00 0.00 10 15 20 25 30 35 40 45 50 55 60 65 Speed (mph) 14
Frequency (%) Route 30 Geodetic Surveying Speed Distribution Route 30 Minimum: 45.5 mph, Maximum: 65.7 mph, Average: 55.4 mph 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 50 55 60 65 Speed (mph) 15
Frequency (%) Route 35 Land Surveying Data 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 25 30 35 40 45 50 55 60 Speed (mph) Average Speed = 35.7 mph Standard Deviation = 6.1 mph 16
Frequency (%) Route 33 Land Surveying Data 25 20 15 10 5 0 30 35 40 45 50 55 60 65 Speed (mph) Average Speed = 46.2 mph Standard Deviation = 6.2 mph 17
Traffic Safety Devices We identified possible low-cost devices that might enhance the safety of workers when they work at short term surveying or inspection jobs (less than 1-2 hours) The idea is to deploy a warning system without wasting too much time and effort. The products we identified are: 1. RoadQuake 2. Turbo Flare 3. Turbe Flare with Electronic Movement Detector 4. Traffic Blanket 5. Barricade Lights 6. Personal Strobe Lights 18
RoadQuake RoadQuake highway rumble strips are effective alarms alerting drivers to slow down approaching a temporary work zone. RoadQuake does not require fasteners or adhesives for installation. 3 pieces (each are 44 long, 12 wide, 13/16 thick at 35 lbs) form a 11 feet long strip. RoadQuake is currently approved in 11 states with tests pending in many others. The current 11 approval are: AL, CO, FL, GA, KS, MN, NM, NV, OK, TN & UT. RoadQuake is designed to be used in where the posted speed does not exceed 60 MPH and the temperature is not less the 40 o F. 19
RoadQuake (cont d) 20
RoadQuake (cont d) Sun et al. (2010) showed that with the use of temporary rumble strips percent of braking vehicles increased by 10.5%, speed of braking vehicles decreased by 3.7% These results show that temporary rumble strips were effective in alerting drivers regarding the workzone ahead. Also, a more qualitative analysis by FHWA research shows that (Morgan, 2003; FHWA/NY/SR-03/140) Use of rumble strips at work zones is effective and sufficient to provide the results required for the usual short duration on most maintenance jobs. The results of various studies in the literature show that rumble strips produces a reduction of 1.5-4 mph in speed (Fontaine, 2006; Sun, 2010). 21
Turbo Flare Turbo Flare is an electronic flare that uses LED light to warn oncoming traffic about the presence of surveyor or worker ahead. It is weather proof and highly durable (resistant to vehicle weight). It can be used either with an orange pennant or a spring cone. 22
Turbo Flare with Electronic Movement Detector Electronic Movement Detector (EMD) can be added to TurboFlare that will notify the worker or surveyor of any interference from vehicles entering into their TurboFlare traffic control pattern/lane closure, or if any flare is removed from the pattern. A constant beep is sent to the receiver attached to the shoulder flap on his/her uniform or belt. The Turbo-pennants that attach to the top of each flare are used to deploy and recover in a single trip to and from the vehicle. 23
Traffic Blanket Traffic Blanket with Amber LEDs. Battery operated with two (2) distinct flashing patterns. Attaches to vehicle with magnets or has eyelets which can be used with rope to attach to vehicle. 24
Barricade Light & Personal Strobe Light 25
Review of Safety Devices Device Installation Time Advantages Disadvantages RoadQuake 5 minutes Driver Awareness Reduced Speed Durable Requires 2 people to install Turbo Flare < 1 minute Inexpensive, easy to deploy Personal Strobe Lights < 1 minute Inexpensive, easy to deploy Can be installed around the signs Barricade Light < 1 minute Inexpensive, easy to deploy Visibility Issues during daytime Durability Issues Visibility issues during daytime 5-10 required to have a desired impact during daytime Traffic Blanket - Driver Awareness By law, the sign should not direct traffic. 26
Frequency (%) Impact of RoadQuake on Speed 40.0 Field Test 1 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 With Rumble Strips Without Rumble Strips 25 30 35 40 45 50 55 60 65 Speed (mph) Location: Route 35, Belmar, NJ Rumble Strips were located upstream of the intersection where the surveying was being conducted 95 percent confidence interval of speed: Without Rumble Strips [33.9, 37.4] With Rumble Strips [32.7, 36.3] Average speed reduced by 1.2 mph 27
Frequency (%) Impact of RoadQuake on Speed 50.0 45.0 40.0 Field Test 2 Location: Route 33, Neptune, NJ 35.0 30.0 25.0 Without Rumble Strips Rumble Strips were located upstream of the intersection where the surveying was being conducted 20.0 15.0 10.0 5.0 0.0 30 35 40 45 50 55 60 65 With Rumble Strips 95 percent confidence interval of speed: Without Rumble Strips [44.8, 47.7] With Rumble Strips [42.1. 45.2] Speed (mph) Average speed reduced by 2.5 mph 28
Next Steps Evaluate the effect of rumble strips with barricade lights. Conduct controlled field data to assess the impact of selected safety devices on drivers awareness / hazard perception. Field tests with and without safety devices will be conducted on 3 different campuses via driver surveys and also video cameras. Finalize safety recommendations based on our findings.